Did you know?
Despite common perceptions, male factors alone are responsible for about 30% of all infertility cases and contribute to another 20% when combined with female factors. This highlights the importance of evaluating both partners in infertility assessments.
Infertility
Researched by:
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Karen Pendergrass
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Karen Pendergrass
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
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Kimberly Eyer
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Kimberly Eyer
Kimberly Eyer, a Registered Nurse with 30 years of nursing experience across diverse settings, including Home Health, ICU, Operating Room Nursing, and Research. Her roles have encompassed Operating Room Nurse, RN First Assistant, and Acting Director of a Same Day Surgery Center. Her specialty areas include Adult Cardiac Surgery, Congenital Cardiac Surgery, Vascular Surgery, and Neurosurgery.
Infertility is the inability to conceive after 12 months of regular, unprotected sex. It affects both men and women and can be due to various physical, hormonal, or genetic factors. Treatments include medication, surgery, assisted reproductive technologies, and lifestyle changes.
Research feed Researched by:
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Karen Pendergrass
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Karen Pendergrass
Fact-checked by:
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Kimberly Eyer
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Kimberly Eyer
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
Overview 
Research Feed Overview
Infertility is a complex reproductive health issue, defined by failing to conceive after 12 months of regular unprotected sex. The criteria may differ depending on factors like age. The World Health Organization identifies it as a global public health concern, affecting about 17.5% of couples globally [x]. Conditions like endometriosis and erectile dysfunction can cause infertility. Identifying these causes is essential for effective treatment.
What female factors are associated with infertility?
| Cause of Female Infertility | Description |
|---|---|
| Ovulatory Disorders | This is the most common cause of female infertility and includes conditions such as polycystic ovary syndrome (PCOS), premature ovarian failure, and hypothalamic dysfunction. |
| Tubal Factors | Blockage or damage to the fallopian tubes can prevent the egg from being fertilized or the fertilized egg from reaching the uterus. This can be due to pelvic inflammatory disease, endometriosis, or previous surgeries. |
| Uterine or Cervical Abnormalities | Structural abnormalities of the uterus or cervix can interfere with implantation or increase the risk of miscarriage. This includes anomalies like fibroids, polyps, or congenital anomalies. |
| Endometriosis | A condition in which the tissue that normally lines the inside of the uterus grows outside it, which can affect the function of the ovaries, uterus, and fallopian tubes. |
What male factors are associated with infertility?
| Cause of Male Infertility | Description |
|---|---|
| Sperm Disorders | Problems with sperm production, function, or delivery, including low sperm count, poor sperm motility, or abnormalities in sperm morphology. |
| Varicocele | Enlargement of the veins within the scrotum that can affect sperm production and function. |
| Hormonal Disorders | Imbalances in hormonal systems such as the hypothalamic-pituitary-gonadal axis can impair sperm production. |
| Ejaculatory and Erectile Dysfunction | Issues with ejaculation or erectile function can interfere with the delivery of sperm. |
Diagnosis
Evaluating infertility involves complex, gender-specific diagnostic tests. In women, doctors assess ovulation, ovarian reserve, and the uterus and fallopian tubes’ condition. They use hysterosalpingography, transvaginal ultrasound, and laparoscopy for these evaluations. For men, the primary diagnostic tool is semen analysis, which checks sperm count, motility, and morphology. Additional male tests may include hormone profiling, ultrasound exams, or genetic testing to detect underlying problems. This tailored approach precisely identifies infertility causes in couples seeking help.
Treatment
Infertility treatment depends on its cause, duration, partner ages, and personal choices. Options range from medication for ovulation and hormone balance to surgery for endometriosis and anatomical issues. If unsuccessful, Assisted Reproductive Technology (ART) like in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) may follow. Lifestyle changes, including diet, exercise, smoking cessation, and reduced alcohol, can also boost fertility.
Implications
Infertility can have profound psychological and social impacts. It is often associated with stigma, emotional distress, and depression. Couples may experience stress in their relationship and personal anxiety. Hence, psychological support and counseling are also integral parts of infertility treatment.
Research Feed
Association of the Cervical Microbiota With Pregnancy Outcome in a Subfertile Population Undergoing In Vitro Fertilization: A Case-Control Study
The study investigated the link between cervical microbiota and IVF outcomes in subfertile women. It found that higher microbial diversity and specific bacterial abundances correlated with successful pregnancy. These insights suggest potential for microbiota-based diagnostics and treatments to enhance IVF success.
What Was Studied?
The study focused on the association between the composition of cervical microbiota and pregnancy outcomes in a subfertile population undergoing in vitro fertilization (IVF). Specifically, it aimed to characterize the cervical microbiota of patients undergoing embryo transfer (ET) and assess whether the composition of these microbiota is associated with the outcomes of the IVF treatments. The study utilized high-throughput sequencing technology to analyze the cervical microbiota and explored factors contributing to the observed compositions.
Who Was Studied?
The participants in this study were infertile female patients undergoing IVF treatment at the Reproductive Center of Shengjing Hospital of China Medical University. The study included 100 patients who met specific inclusion criteria: aged between 20 to 40, undergoing assisted reproductive technology with their own gametes, and transferring two cleavage-stage embryos. Patients with autoimmune, endocrine, cervical, or endometrial diseases or blood contamination of collected samples were excluded.
What Were the Most Important Findings?
Diversity of Microbiota: Higher α diversity in the cervical microbiota was observed in the clinical pregnancy groups compared to non-pregnancy groups, especially in fresh IVF-ET cycles. This suggests a richer microbial environment may be associated with positive pregnancy outcomes.
Microbial Composition: Significant differences in the β diversity (overall microbiota composition) were noted between pregnancy outcomes in both fresh and frozen-thawed cycles, with fresh cycles showing a more pronounced difference.
Specific Microorganisms: In fresh cycles, certain bacterial genera such as Lactobacillus, Akkermansia, Desulfovibrio, Atopobium, and Gardnerella showed different abundances between pregnant and non-pregnant groups. Lactobacillus, in particular, was found to be negatively correlated with other bacteria but positively correlated with serum estradiol levels, which are critical for pregnancy.
Predictive Analysis: Logistic regression analysis indicated that the composition of the cervical microbiota on the day of ET is significantly associated with clinical pregnancy outcomes.
What Are the Greatest Implications of This Study?
Clinical Implications: The study implies that understanding and potentially manipulating the cervical microbiota could enhance IVF success rates. This could lead to new diagnostic tools or treatment strategies, such as prebiotic or probiotic interventions to optimize the cervical microbial environment before embryo transfer.
Research Implications: The findings stress the need for more in-depth research into the role of the microbiota in fertility and pregnancy outcomes. It calls for longitudinal studies to explore how cervical microbiota changes over time and its interactions with hormonal levels and other physiological factors during fertility treatments.
Therapeutic Implications: Given the association between specific bacterial populations and pregnancy success, there might be potential for developing microbial-based therapies or supplements to support IVF procedures, enhancing the uterine environment for embryo implantation and pregnancy continuation.
This study opens up new pathways for both understanding and improving reproductive health interventions in subfertile populations undergoing assisted reproductive technologies.
Characteristics of gut microbiota in patients with asthenozoospermia: a Chinese pilot study
The study explored gut microbiota differences in men with asthenozoospermia (AS) compared to healthy controls, finding significant disparities in microbial diversity and composition. Key bacteria correlated negatively with sperm motility, suggesting gut microbiota may influence male fertility, potentially offering new targets for diagnosing and treating AS.
What was studied?
The study investigated the characteristics of gut microbiota in patients with asthenozoospermia (AS), a common cause of male infertility characterized by reduced sperm motility. It aimed to identify differences in gut microbiota composition between AS patients and healthy controls and explore the potential links between gut microbiota and the development of AS.
Who was studied?
The study involved 108 men, including 60 patients diagnosed with isolated AS and 48 healthy men serving as controls. These participants were recruited from the outpatient department of Tianjin Medical University General Hospital. Men with AS were compared against healthy controls with normal semen parameters.
What were the most important findings?
Diversity and Composition: AS patients exhibited significantly lower alpha diversity in their gut microbiota and distinct beta diversity compared to healthy controls. Specific bacteria such as Escherichia_Shigella and various members of the Prevotellaceae family were notably different between the groups.
Correlation with Sperm Mobility: Certain key genera identified were negatively correlated with sperm motility parameters in AS patients, suggesting a potential impact of these microbial communities on sperm function.
Predicted Metabolic Pathways: The study predicted significant differences in metabolic pathways such as steroid biosynthesis and meiosis, potentially influencing the physiological processes related to sperm motility and overall reproductive health.
What are the greatest implications of this study?
The findings suggest that gut microbiota dysbiosis might be linked to the development of asthenozoospermia, possibly through effects on systemic inflammation, nutrient synthesis, and hormonal balance. This could lead to new diagnostic and therapeutic approaches, where modulation of gut microbiota could become part of treating or managing male infertility. The study supports the concept of the gut-testis axis, highlighting the broader systemic impact of gut health. Future research could focus on confirming these findings and exploring gut microbiota modification as a therapeutic strategy for AS.
Endometriosis
Endometriosis involves ectopic endometrial tissue causing pain and infertility. Validated and Promising Interventions include Hyperbaric Oxygen Therapy (HBOT), Low Nickel Diet, and Metronidazole therapy.
Erectile Dysfunction
Erectile dysfunction (ED) involves the consistent inability to sustain an erection, frequently connected to broader health issues and disturbances in the gut microbiome.
Infertility
Infertility is the inability to conceive after 12 months of regular, unprotected sex. It affects both men and women and can be due to various physical, hormonal, or genetic factors. Treatments include medication, surgery, assisted reproductive technologies, and lifestyle changes.
Endometriosis
Endometriosis involves ectopic endometrial tissue causing pain and infertility. Validated and Promising Interventions include Hyperbaric Oxygen Therapy (HBOT), Low Nickel Diet, and Metronidazole therapy.